Ultrasound Irradiation Promoted Large-Scale Preparation in Aqueous Media and Antioxidant Activity of Azoles

The scaled-up preparation of 1H-pyrazole, 1-phenylpyrazole and isoxazole via sonocatalysis is reported. The products were isolated in good yields in short time reaction. These compounds had been assayed for antioxidant activity by ORAC and DPPH methodologies. The results showed that only 1-phenylpyrazole presented good antioxidant activity compared with Trolox(R).

Synthesis of seleno-carbohydrates derived from D-galactose

The synthesis of seleno-galactopyranosides in a short and efficient manner is described, starting from the parent carbohydrate D-galactose. The approach described allows the synthesis of small libraries of compounds with a number of structural variations at the group attached to selenium. Compounds with aryl, propargyl, allyl, acyl, and alkyl substituents are described. (C) 2010 Elsevier Ltd. All rights reserved.

New antitumoral agents I: In vitro anticancer activity and in vivo acute toxicity of synthetic 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadien-3-one and derivatives

This paper describes a new method for the preparation of 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadien-3-one 1 and its derivatives 2-5. This set of synthetic compounds exhibited high antitumoral activities regarding in vitro screening against several human tumor cell lines as lung carcinoma NCI-460, melanoma UACC-62, breast MCF-7, colon HT-29, renal 786-O, ovarian OVCAR-03 and ovarian expressing the resistance phenotype for adriamycin NCI-ADR/ RES, prostate PC-3, and leukemia K-562. Compounds were also tested against murine tumor cell line B16F10 melanoma and lymphocytic leukemia L1210 as well as to their effect toward normal macrophages. Specific activity against colon cancer cells HT-29 was observed for all tested compounds and suggests further studies with models of colon cancer. Compounds 1, 2, and 4 showed significant cytotoxic activity with IC(50) values <= 2.3 mu M for all human cancer cell lines. Intraperitoneal acute administration of compound 1 and 2 showed very low toxicity rate. (C) 2010 Elsevier Ltd. All rights reserved.

Chiral Triphenylprolinol Ligands for the Efficient Catalytic Asymmetric Arylation of Aldehydes

The synthesis of new chiral amino alcohols by Heck arylation of an enecarbamate is described. These compounds were used as chiral ligands for the catalytic asymmetric arylation of aldehydes and can be easily recovered. Chiral, nonracemic diarylmethanols were obtained in high yields and enantioselectivities.

Synthesis of 5 `-seleno-xylofuranosides

The synthesis of selenium derivatives of naturally occurring chiral molecules is becoming increasingly important in recent years. In this context, we describe herein an easy, straightforward synthetic route for the preparation of a series of chiral seleno-furanosides, starting from the readily available carbohydrate D-xylose. In addition, selected compounds were screened as inhibitors of the delta-aminolevulinate dehyclratase (delta-ALA-D) enzyme. Diselenide 4 was found to reduce significantly the enzymatic activity, while seleno-furanoside la increased delta-ALA-D activity. (C) 2010 Elsevier Ltd. All rights reserved.

Cruzain inhibition by hydroxymethylnitrofurazone and nitrofurazone: investigation of a new target in Trypanosoma cruzi

Nitrofurazone (NF) and its derivative, hydroxymethylnitrofurazone (NFOH), have presented antichagasic activity. NFOH has higher activity and lower mutagenicity. The aim of this work was to assess whether NF and its derivative NFOH would also be inhibitors of cruzain, besides their trypanothione reductase inhibitory activity. In vitro cruzain inhibition tests were performed for both compounds, and the 50% inhibitory concentration (IC(50)) for NF and NFOH presented values of 22.83 +/- 1.2 mu M and 10.55 +/- 0.81 mu M, respectively. AM1 semi-empirical molecular modeling studies were performed to understand the activity of the compounds, corroborating the observed cruzain inhibitory activity.

Highly efficient palladium-catalyzed Suzuki-Miyaura reactions of potassium aryltrifluoroborates with 5-iodo-1,3-dioxin-4-ones in water: an approach to alpha-aryl-beta-ketoesters

The high efficient palladium-catalyzed Suzuki-Miyaura reactions of potassium aryltrifluoroborates 3 with 5-iodo-1,3-dioxin-4-ones 2a-b in water as only solvent in the presence of n-Bu(4)NOH as base is reported. The respective 5-aryl-1,3-dioxin-4-ones 4a-n were obtained in good to excellent yields. The catalyst system provides high efficiency at low load using electronically diverse coupling partners. The obtained 2,2,6-trimethyl-5-aryl-1,3-dioxin-4-ones were transformed into corresponding alpha-aryl-beta-ketoesters 6 by reaction with an alcohol in the absence of solvent. (C) 2009 Elsevier Ltd. All rights reserved.

Molecular modeling as a promising tool to study dendrimer prodrugs delivery

Molecular modeling methodologies were applied to perform preliminary studies concerning the release of active agents from potentially antichagasic and antileishmanial dendrimer prodrugs. The dendrimer was designed having myo-inositol as a core, L-malic acid as a spacer group, and hydroxymethylnitrofurazone (NFOH), 3-hydroxyflavone or quercetin, as active compounds. Each dendrimer presented a particular behavior concerning to the following investigated properties: spatial hindrance, map of electrostatic potential (MEP), and the lowest unoccupied molecular orbital energy (E(LUMO)). Additionally, the findings suggested that the carbonyl group next to the active agent seems to be the most promising ester breaking point. (C) 2009 Elsevier B.V. All rights reserved.

Novel deoxy-selenylconduritols: chemoenzymatic synthesis and biological evaluation

The first synthesis of two selenyldeoxycyclitols (4-bromo-2-phenylselenyl conduritol F and 6-phenylselenylconduritol F) is reported via a chemoenzymatic enantioselective route. The key step of the synthesis is the selenolysis of a vinyl epoxide. The new compounds were evaluated for their capacity to inhibit the growth of different microorganisms using a modification of the agar diffusion technique with thin layer chromatography plates as support. (C) 2009 Elsevier Ltd. All rights reserved.

Consecutive biocatalysis-palladium catalysis II: Synthesis of conduritol-alkyne conjugates

The palladium-catalyzed cross-coupling reaction of potassium alkynyltrifluoroborates with a chemoenzymatically derived deoxyconduritol is described. Six new compounds were synthesized in moderate to good yields. The alkynyl cross-coupling reaction can be effected using 10 mol% of Pd(PPh(3))(4) as Catalyst in toluene-H(2)O in the presence Of Cs(2)CO(3) as the inorganic base. (C) 2009 Elsevier B.V. All rights reserved.

Synthesis of selenium- and tellurium-containing nucleosides derived from uridine

The synthesis of selenium- and tellurium-containing nucleosides, derived from uridine is described herein. These compounds were prepared in a concise and short synthetic route in good yields, by nucleophilic substitution of a tosylate group by organoselenium nucleophiles. (C) 2009 Elsevier Ltd. All rights reserved.

Development of a Stability-Indicating LC Assay Method for Determination of Chloroquine

A simple and rapid development of a stability-indicating LC method for determination of chloroquine diphosphate in the presence of its hydrolysis, oxidative and photolysis degradation products is described. Stress testing showed that chloroquine diphosphate was degraded under basic conditions and by photolytic treatment but was stable under the other stress conditions investigated. Separation of the drug from its degradation products was achieved with a Nova Pack C18 column, 0.01 M PIC B7 and acetonitrile (40:60 v/v) pH 3.6, as mobile phase. Response was linear over the range 0.08-5.70 mu g mL(-1) (r = 0.996), with limits of detection and quantification (LOD and LOQ) of 0.17 and 0.35 mu g mL(-1), respectively.

Quantitative Determination of Dimethylaminoethanol in Cosmetic Formulations by Nuclear Magnetic Resonance Spectroscopy

A nuclear magnetic resonance (NMR) spectroscopic method was validated for the quantitative determination of dimethylaminoethanol (DMAE) in cosmetic formulations. The linearity in the range from 0.5000 to 1.5000 g (DMAE salt/mass maleic acid) presents a correlation coefficient > 0.99 for all DMAE salts. The repeatability (intraday), expressed as relative standard deviation, ranged from 1.08 to 1.44% for samples and 1.31 to 1.88% for raw materials. The detection limit and quantitation limit were 0.0017 and 0.0051 g for DMAE, 0.0018 and 0.0054 g for DMAE bitartrate, and 0.0023 and 0.0071 g for DMAE acetamidobenzoate, respectively. The proposed method is simple, precise, and accurate and can be used in the quality control of raw materials and cosmetic gels containing these compounds as active substances.

Organocatalytic asymmetric aldol reactions mediated by a cysteine-derived prolinamide

In this Letter, a cysteine-derived prolinamide is described to act as a robust and effective organocatalyst for enantioselective aldol reactions. (c) 2008 Elsevier Ltd. All rights reserved.

Evaluation of gastroprotective activity of Plinia edulis (Vell.) Sobral (Myrtaceae) leaves in rats

Plinia edulis, an arboreous species popularly known as ""cambuca"", is native to the Brazilian Atlantic Rain Forest. Despite its traditional uses, no reports are available on the safety of this utilization or on the relationship between the antiulcer activity of its extract and its phytochemical compounds. This paper reports on the investigation of the acute toxicity and gastroprotective effect of the aqueous ethanol extract of leaves of Plinia edulis on HCl/ethanol-induced ulcers. In order to correlate the secondary metabolites and the efficacy of the crude drug in traditional medicine, the extract was submitted to chromatographic fractionation after solvent partition. The extract did not show acute toxicity in mice treated with 5 g/kg p.o.. but exhibited significant antiulcer activity in rats at doses of 100, 200, and 400 mg/kg p.o., more active than the reference drug lansoprazole. The ethyl acetate fraction yielded P-amyrin, oleanolic acid, ursolic acid, and maslinic acid, which were identified based on spectrometric analyses. Since antiulcerogenic activity is not restricted to one class of compounds in plants, the triterpenoids isolated in the extract can be associated with the observed effect. (C) 2008 Elsevier Ireland Ltd. All rights reserved.